The Effect of Alcohol on Sleep

We’ve all seen someone comatose with drink, passed out at a party, or heavy-lidded at a bar. In times gone by, people even used to slip children a sip of gin to make them sleep. Unsurprising, therefore, that some insomniacs have resorted to the age-old method of slugging a ‘nightcap’ before bed. However, quite apart from all the other problems with self-medicating in this manner, it seems that drinking before bed can actually be a very bad idea if you want to get a healthy night’s sleep. While alcohol may initially knock you out for the count, the kind of sleep it brings is neither restful nor prolonged.

Why Alcohol Makes You Sleepy

We all know that alcohol is bad for us. Drinking too much of it can significantly shorten your lifespan – so much so that insurance companies will often ask questions about average alcohol intake before offering a premium on things like life or medical insurance. However, it can’t be denied that alcohol can make us sleepy. When your sleeping patterns are shot to pieces, and you’re desperate for some rest, alcohol seems like a quick and effective way to shut down your brain. Unfortunately, what alcohol is doing is not so much promoting proper sleep as artificially depressing your central nervous system – a situation which your body feels compelled to rectify as you sober up through the night (more on that later). Sometimes, in fairness, you feel extra-sleepy after a boozy night out because such things are naturally fatiguing. Other times, however, your sleepiness has more to do with the muscle-relaxing effects of alcohol, and its tendency to shut down or depress bits of your brain. It’s not a ‘natural’ way to fall asleep, as the quality of said sleep indicates.

Disrupted Sleep with Alcohol

During a study carried out by the University Of Melbourne in Australia, volunteers were fed either a ‘nightcap’ of vodka or a nonalcoholic placebo before bed, and then had their brainwaves measured while they slept. The researchers discovered that those who drank before bed displayed ‘alpha’ brainwaves in addition to the ‘delta’ waves you’d expect to see during sleep. ‘Alpha’ brainwaves occur when the brain is awake, but in ‘metabolic break mode’ – i.e. resting. What this means in practice is that the brains of people who drink before sleep are not ‘concentrating’ fully on all the things they need sleep for. Any of the positive delta wave effects are offset by the wakeful alpha waves. This kind of pattern is only seen otherwise in people who have chronic pain conditions, or who are suffering from great anxiety – it’s the kind of sleep pattern which can see you snap out of sleep at any moment, and then have trouble drifting off again. Which is precisely what happens as people start to sober up.

Sobering Up And Waking Up

While you’re drunk, many of your bodies systems are depressed, allowing you to remain comotose. However, as you sober up and your blood-alcohol levels drop, your body and brain go through some significant metabolic changes. As the alcohol drains away from your brain, previously repressed parts like the hippocampus will metaphorically shake themselves off and reboot – causing disruption to your brainwaves, and sometimes jerking you out of sleep. Furthermore, your body will start to take stock of the state your drinking has left it in – often leading to demands for further blood sugars, more water, and that kind of thing. And then there’s the hangover. Nobody is entirely sure what causes all of the delightful symptoms of a hangover. For many years, dehydration got the brunt of the blame, but modern scientists believe that your hangover is a lot more complex than this (as all of us who diligently drink water throughout the night, yet still wake up with hangovers, are all too aware). The irritation of your stomach lining caused by alcohol is responsible for waking up many nighttime drinkers, and the other symptoms of your rebooting body and your hangover make it very hard indeed to get back to sleep. All in all, while drinking knocks you out nicely, the sleep it gives you is in no way restful, and it probably won’t last you through the night. An alcohol-induced sleep is confused, punctuated with awakenings, and ends with a disgruntled body which is not only exhausted, but hungover to boot. Best to find more natural methods of getting off to sleep.

Guest Author: Anne James is a freelance writer. She previously held a management role in healthcare.